Llew I sent a couple of oil samples in for testing recently one being unused Joe Gibbs BR and a sample from a 2lt rally engine and the new oil came back with abnormal levels of phosphorous and zinc with them believing they were too high for normal standards lololol

How many turns out were the idle mixture screws before you changed the idle jet 2.5psi is still too highForget about what the hp figures are from a flow bench as they're just a pipe dream and don't mean that much as there are far too many variables

I know the 50's were about right in relation to idle mixture screw adjustment but the 55's are still ok. I quoted the flow bench figure to explain the low air speed, nothing more. 2.5lb is fine, everyone has a different opinion on the matter. In my case I trust the person who built & tuned my engine, Peter Baguley from Performance Thumpers & Escorts.

ratta tat tat wrote:2.5lbs. Since willowbank I have gone a size bigger in my idle jets to 55F9 because the carbs were backfiring at low revs on hwy and around town due to low air speed. Head bench flowed 191hp

Haydon Weber needle and seats are designed to run 1.5-2psi or they will "fuel up" and fume which is what you car was doing at Willowbank. Flow bench figures don't mean anything to explain the idle as it all comes down to how it is tuned

Danny M wrote:Haydon Weber needle and seats are designed to run 1.5-2psi or they will "fuel up" and fume which is what you car was doing at Willowbank. Flow bench figures don't mean anything to explain the idle as it all comes down to how it is tuned

You're either misreading my posts or you're trolling I'll leave it at that